New research provides insight into the evolution of cooperation, and shows …

If you ever sit back and wonder what it might have been like to live in the late Pleistocene, you’re not alone. That's right about when humans emerged from a severe population bottleneck and began to expand globally. But, apparently, life back then might not have been too different than how we live today (that is, without the cars, the written language, and of course, the smartphone). In this week’s Nature, a group of researchers suggest that we share many social characteristics with humans that lived in the late Pleistocene, and that these ancient humans may have paved the way for us to cooperate with each other.

Modern human social networks share several features, whether they operate within a group of schoolchildren in San Francisco or a community of millworkers in Bulgaria. The number of social ties a person has, the probability that two of a person’s friends are also friends, and the inclination for similar people to be connected are all very regular across groups of people living very different lives in far-flung places.

So, the researchers asked, are these traits universal to all groups of humans, or are they merely byproducts of our modern world? They also wanted to understand the social network traits that allowed cooperation to develop in ancient communities.

Of course, the researchers couldn’t poll a group of ancient humans, so they had to find a community living today that has a lifestyle that closely resembles those of people who might have lived 130,000 years ago. They chose the Hadza, a group of hunter-gatherers that live in Tanzania and are very insulated from industrialization and other modern influences. The Hadza community functions much like ancient hunter-gatherer groups did, by cooperating and sharing resources like food and child care. Hadza society is organized into camps, which are taken up and abandoned regularly; the makeup of each camp also changes often, with individuals leaving one camp to join another.

The researchers visited 17 Hadza camps and surveyed 205 adults. First, they looked at individuals’ donations of honey sticks to other community members. They also asked questions like, “With whom would you like to live after this camp ends?” From the answers, the researchers constructed a model of the Hadza social network.

Many features of the hunter-gatherer network are very similar to those of modern, industrialized communities. Those who live farther away from each other are less likely to name each other as friends. Individuals who name more friends are also named more frequently by others, even among people they did not claim as their friends. People who resemble each other in some physical way tend to be connected as well; for Hadza people, similarity in age, body fat, and handgrip strength increases the likelihood of friendship.

There are also several features of the Hadza social network that may facilitate extensive cooperation. People that cooperate (in this case, by donating more honey sticks) are connected to other cooperators, while non-cooperators tend to be connected to each other. This type of clustering allows for cooperators to benefit from others’ large donations and increase in the population.

Evolutionary biologists have predicted that, for cooperation to evolve and spread, there should be more variance in cooperative behavior between groups than within groups. This is another example of clustering, and it allows for differences in the productivity and fitness of groups with different cooperation levels. And indeed, in Hadza society, there is more variance in cooperation between different camps than within camps.

From these results, two things are clear; first, that many of the universal characteristics of modern social networks also hold true for the Hadza, suggesting that these traits may have also governed the social networks of ancient humans. Second, several social features that have been predicted to facilitate the evolution and spread of cooperation are present in Hadza communities.

Clearly, ancient societies likely differed from the Hadza in many ways, but this community of hunter-gatherers may be as close as we can now get to the structure and characteristics of extinct human communities. Cooperation is one of the most heavily researched, yet poorly understood aspects of human life, and this research gives us insight into the type of community in which this phenomenon could have evolved and spread.

Each face has a unique smoke signal associated with it. When the lady in the photo wants to contact somebody on the non-Web version of Facebook, she builds a smoky fire, then sends that signal. Her daughter sees the signal, then says to her friends "Geez, I wish my mom wasn't on Facebook!"

It's a commonplace that what really matters to people is friends and family. If we're to plan a meaningful future, we may want to have a clearer sense of how we actually want to live. If we can discover underlying, transhistorical patterns to social organization, that would be worth taking into account.

Why do we insist on spending million$ on research to justify how we behave today? The future, not the past, is going to tell us the benefits of our current social networking.

Because looking at where we come from provides more evidence to extrapolate from to attempt a guess at where we're going. And let's also not the cliche "those who don't learn from the past are doomed to repeat it," which is absolutely true. Just look at the US, via lack of enforcement of the rules set in place after the Great Depression, and lo-and-behold, we have another extremely well-orchestrated collapse that actively benefits the top, and has the gap with the other 95% widening every day. All because government chose to ignore the past (or maybe they did learn from it; this depression has been extremely well-orchestrated in that we don't seem to be approaching a cascade failure of any kind, but the poor get poorer, and the rich get richer, as intended...)

I would also point out, it's not justification, it's explanation. We _know_ what we do today, but _why_ do we do it, and for how long? What are the origins of that behavior? Did it help us previously? In what ways? Bottom line, though, is that knowledge is its own end. We know more now than we did before the research. It was therefor worth the money.

Social networks are a construct inherent to Human societies.Social networking tools are as old as history (the written scroll/clay tablet/letter being the first tool I can think of).Social networking platforms such as Facebook are a modern invention by advertisers to make huge profits out of natural Human instincts (quite like the porn industry).

Kate Shaw Yoshida / Kate is a science writer for Ars Technica. She recently earned a dual Ph.D. in Zoology and Ecology, Evolutionary Biology and Behavior from Michigan State University, studying the social behavior of wild spotted hyenas.